Marine steam-turbine.



PATENTBD SBPTfa, 1904.

G. A. PARSONS. MARINE STEAM TURBINE.

APPLICATION FILED JUNE 27, 1902.

[SHEETS-SHEET 1.

N0 MODEL.

No. 769,272. PATENTED SEPT. 6, 1904.

O. A. PARSONS. 'MARINE STEAM TURBINE.

- APPLICATION FILED JUNE 27, 1902.

, N0 MODEL, 2 SHEETS-SHEET 2. S

J ttcsllx I QC/dbr Civics)? 3 0 SUNITEDI STATES Patented September 6,1904.

PATENT OFFICE;

MARINE STEAM-TURBINE.

SPECIFICATION forming part of Letters Patent No. 769,272, datedSeptember 6, 1904. 1 Application filed June 27, 1902; Serial No.113,501- (No model.)

To all whom it may concern:

Be it known that I, OHARLEs ALGERNON PAR- soNs, engineer, a subject ofthe King of Great Britain and Ireland, residing at HeatonWorks,

Newcastle-upon-Tyne, in the county of Northumberland, England, haveinvented certain new and useful Improvements in Marine Steam-Turbines,(for which I have made application for Letters Patent in Great Britain,No. 24,515, dated December 2, 1901; in France, No. 317,003, datedDecember 18,1901; in Germany, application filed December 19, 1901,

very low rates of speed and correspondinglyvery reduced horse-powers.The present arrangement, however, is for obtaining economies at,cruising speeds, which are often above the limits of rotational speedsat which reciprocating engines can safely be worked for long periods oftime.

My invention is intended to provide acornbination of cruising andfull-power steam-turbines and is an improvement upon the invention whichforms the subject of the abovementioned application, Serial No. 15,163.It

is also an improvement upon the patent already granted to me, No.608,969, dated August 9, 1898.

To carry out the invention'in warships such as battle-ships, cruisers,or torpedo-boat destroyers'the main turbines consist of one high and twolow pressure turbines driving separate shafts. The low-pressure turbinesare coupled to two cruising-speed turbines secured to prolongations ofthe main low-pressure-turbine shafts and carry small and numerous rowsof blades. These'cruising-turbines consist of a high-pressure turbineand an ntermediate-pressure turbine. They are of such capacity that theycan only pass thecomparatively small volume of steam required forcruising purposes. When cruising at the lower rates of speed, the steamfrom the boiler passes successively through the high-pressure turbineand the intermediate-pressure cruising-turbines and thence to the mainhighpressure turbine and on through the two lowpressure turbines to thecondensers, thus securing a very high degree of expansion of steam and.high coefficients of efficiency in the turbines when they are running atreduced speeds. a portion or the whole of the boiler-steam is admittedto the intermediate-pressure cruis- VVhen higher speeds are required,

the main turbines. Under the latter condition I prefer to run thehighepressure cruis' .1ngturbine idly, a backflow of steam from theintermediate pressure cruising turbine into the high-pressure turbinebeing prevented by a non-return valve in the pipe which connects thesetwo turbines. Inorder that the high-pressure turbine shall then revolvewith very little resistance, I may place it in direct valve-controlledcommunication With the condenser. It will then run idly in thecondenser-vacumn. The non-return valve above referred to maybe, however,dispensed withand the high-pressure cruising-turbine run idly inhigh-pressure steam; but as this turbine is relatively small itsresistance is inconsiderable. Still higher rates of cruising speed canbe obtained by admitting additional boiler-steam into the mainhigh-pressure and low-pressure turbines. It is desirable to interposenon-return valves between all the turbines to prevent a backfiow ofsteam into the higher-pressure turbines when steam at boilerpressure isadmitted directly to the main turbines. For obtaining intermediategrades of speed between those above mentioned I may provide the high andintermediate cruising turbines with steam-inlets at intermediatepositions in their lengths. The cruising-turbines are perfectlysteam-balanced in themselves and are coupled to the low-pressureturbine-shafts by any suitable coupling, either fixed or detachable.

Referring now to the accompanying draw;

.i do

ings, Figure 1 is a plan of the turbine arrangement, the piping beingshown diagrammatically only. Fig. 2 is an elevation of a portion of thepiping to the high-pressure cruising-turbine. Fig. 3 is a sectional Viewof the non-return valve drawn to an enlarged scale.

The main turbine set consists of a highpressure turbine a, mounted uponthe central shaft y, and two low-pressure turbines b and 0, mounted uponshafts m and 2, respectively. The shafts m and 2 are extended forward ofthe low-pressureturbines and have mounted upon them the cruising-speedturbines (Z and e, of which the former is the high-pressure turbine andthe latter the intermediate-pressure turbine. The turbines (Z and e havesmall and numerous rows of blades and are'of' such capacity that theycan only deal with the comparatively small volume of steam required forcruising purposes. When it is desired to propel the vessel at low ratesof speed, steam from the main steam-pipe f passes by Way of thestop-valve ]L, the branch pipe j, pipe t', T-piece 70, valve m, (seeFig. 2,) and pipe n to the highpressure turbine (Z. After passingthrough this turbine the steam flows through the pipe 0 to theintermediate turbine e, thence by pipe p to the main highpressureturbine a, and thence by pipes qq to the low-pressure turbines b and cand by way of the exhaust-bends 1* 1" into the condensers s s. The steamthus passes through all the turbines in series into the condenser, andthereby secures a very high degree of expansion of steam and highcoefiicient of efficiency in the turbines when they are running at slowspeeds. It will be seen that this follows from introducing a much largernumber of steps by employing additional turbines. hen asomewhat-increased rate of speed is required, additional steam atboiler-pressure may be admittedto the high-pressure turbine d at a pointintermediate in its length by way of the valve t and steam-pipe it. Thenhigher rates of speed than those above referred are required, a portionor the whole of the boiler-steam is admitted to the intermediate turbinec by the steam-pipe r, T-piece w, and pipe 2. In this case I mayrun theturbine cZ'idly in the highprcssure steam communicated to it from theturbine 6 through the pipe 0; but I prefer to place a non-return valve 3in the pipe 0 to prevent backflow of steam into the high-pressureturbine. This valve is hereinafter described in detail with reference toFig. 3 of the drawings. As the high-pressure turbine is relativelysmall, its resistance to rotation in highpressure steam isinconsidcrable. In some cases, however, I connect it directly with thecondenser by means of a suitable valve-controlled pipe, (not shown inthe drawings,) so that it may rotate idly in the condenservacuum. Theturbineemay also be provided With an intermediate live-steamadmissionpipe 4 and valve 5 for the same purpose as the pipe a and valve7?. The shafts to which the turbines (Z and are secured may bedetachably coupled to the shafts .1: and .2, so that the turbines may bestopped, if desired, when the main turbines alone are in operation.Still higher rates of speed can be obtained by admitting steam directfrom the boiler to the main high-pressure turbine (r. This may beeffected by means of the branch pipe 3', stop-valve 7, breeches-pi m 8,and the two steam-pipes 9 9. To prevent a backflow of steam from themain high-pressure turbine a into the intermediate-pressure turbine w, anon-return valve 11, similar in construction to but larger than thevalve 3, is interposed in the pipe p.

In some cases where even higher rates of speed than above referred toare desired l supply steam at boiler-pressure to the main low-pressureturbines by the valve-controlled pipes 12 12, and I employ non-returnvalves 13 13 in the pipes q 1 to prevent a baelrllow of steam into themain high-pressure turbine.

The turbine and piping arrangements are only shown diagrammatically inFig. 1, and the arrangement for reversing the turbines and operatingauxiliary machinery, which form no part of the present invention, areomitted, so that the drawing may be more clearly understood.

When the turbine set consists of high-pressure, intermediate-pressure,and low-pressure turbines on three shafts, as used on the Tum- ?)z'n/iaand described in the specification accompanyingmy Serial No. 620,719,filed .lanuary 26, 1897, the additional turbine set consists,preferably,of one cruising-turbi ne only, with a non-return valve in thepiping which connects the turbine in series with the turbines of themainset. The turbine which comprises the additional set is conveniently mounted upon an extension of the center low-pressure-turbine shaft.

Although I have only mentioned two cruising-turbines in the caseillustrated in Fig. 1, I do not limit the number to two. Larger n umbersof cruising-turbines and different arrangements and graduations may beused, according to the circumstances of the case, so long as theseturbines are additional to the turbine sets forming the main engines andare of capacity adapted to cut down the steam used to that required forcruising purposes.

The non-return valve 3, hereinbefore referred to, is illustrated in Fig.3. .l,l1el1anged neck 16 of the valve-chest opens toward thehigh-pressure turbine (Z, and the neck 17 opens toward theintermediate-pressure turbine a.

When the pressure of the steam at the exhaust end of the turbine (Z isgreater than that at the inlet end of the turbine 11, it lifts the valveagainst the tension of a very light spring 15, attached to the end of apivoted valve-lever 14, thereby enabling a flow of steam to capacitymounted upon a corresponding numtake place from the high-pressureturbine to the intermediate-pressure turbine. When, however, steamdirect from the boiler is ad: mitted to the intermediate-pressureturbine, the pressure of steam; there will be in excess of'theexhaust-pressure of the high-pressure turbine, and the valve 3 willautomatically close and prevent a bac'kflow of steam to thehigh-pressure turbine. The other non-return valves 11, 13, and 13 are ofthe same construe-- tion as and they operate in a similar manner to thevalve 3. Expansion-joints 18 may be provided between the non-returnvalves and the-turbines, as seen in Fig; 1.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is Y 1. A system of turbines for propellingvessels consisting of a main turbine set for propelling the vessel withhigh economy at fast speeds, and an additional turbine set adapted to beput in series with the main turbine set when the vessel is to bepropelled with high economy at cruising and low speeds, and automaticmeans for preventing a backflow of steam from the main turbine set tothe additional turbine set when the former set is propelling the vesselat fast speed, substantially as described.

2. A system of turbines for propellingvessels, consisting of a mainturbine set for pro;

pelling the vessel with high economy at fast speeds and an additionalturbine set adapted to be put in series with the main turbine set forpropelling the vessel with high economy at cruising and slow speeds, theformer set comprising a plurality of turbines of large ber ofpropeller-shafts, and the latter set comprising a plurality of'turbinesof relatively small capacity mounted upon extensions of thepropellerrshafts, substantially as set forth.

3. A system of turbines for propelling vessels, consisting of a mainturbine set for propelling thevessel with high economy at fast speedsand an additional turbine set adapted to be put in series with the mainturbine set for propelling the vessel with high economy at cruising andslow speeds, the main set comprislng a high-pressure and twolow-pressure turbines of. large capacity mounted upon separatepropeller-shafts, and the additional set comprising a high-pressureturbine and an intermediate-pressure turbine mounted uponintermediate-pressure turbine, piping con- 'nectlng theadditionalturbine 1n serles wlth the main turbine set, non-return valvesin said piping between the turbines, and valvecontrolled live-steaminlets to each turbine of both sets, substantially as set forth.

5. A system of turbines for propelling vessels, consisting of a mainturbine set for propelling the vessel with high economy at fast speedsand an additional turbine set for pro' pelling the vessel withhigh-economy at oruising and slow speeds, the main set comprising aplurality of turbines of large capacity and the additional setcomprising a plurality of turbines of relatively small capacity, pipingputting the cruising-turbines in series with the mainturbines,non-return valves in this piping between the turbines of bothsets,

valve-controlled live-steam inlets to each turbine, and additionallive-steam inlets situated at intermediatepositions in the lengths ofthe turbines of the cruising set, substantially as set forth.

In witness whereof I have hereunto set my hand in presence of twowitnesses. 4

CHARLES ALGERNON PARSONS. Witnesses: 1

, HENRY GRAHAM DAKYNS, J unr.,

WILLIAM MENZIEs JOHNSTON.

